Method and apparatus for manufacturing flexible organic EL display

ABSTRACT

A whole organic EL display fabricating apparatus is provided inside a vacuum chamber. In this case, a first patterning unit B through a third patterning unit D for sequentially forming luminescent layer patterns of GREEN, BLUE, and RED on an anode pattern on a strip-shaped flexible substrate  1 , and a fourth patterning unit E for forming a cathode pattern on the subsequent stage are provided. The first patterning unit B is provided with a first cooling can  21  and a vacuum vapor deposition unit below for forming the luminescent layer pattern of GREEN. The structures of the second patterning unit through the fourth patterning unit are similar to that of the first patterning unit. In fabricating a display, the substrate  1  is caused to travel from the first cooling can  21  toward a fourth cooling can  64  by the roll-to-roll system.

This application claims priority to PCT Application No. PCT/JP00/04551,filed Jul. 7, 2000, which claims the benefit of Japanese Application No.11-192928, filed Jul. 7, 1999. Both PCT Application No. PCT/JP00/04551and Japanese Application No. 11-192928 are incorporated herein byreference to the extent permitted by law.

1. Technical Field

This invention relates to a method and apparatus for fabricating anorganic EL (electroluminescence) display utilized as a panel lightsource, a display panel or the like, and particularly to a method andapparatus which enables continuous and efficient fabrication of aflexible organic EL display having a cathode, a luminescent layer madeof an organic substance and an anode on an optically flexible substrate.

2. Background Art

An organic EL element is an element of a thin film type having a firstelectrode (anode or cathode) formed on a substrate, an organic layer(single layer portion or organic multilayer portion), that is, aluminescent layer, containing an organic luminescent substance stackedthereon, and a second electrode (cathod or anode) stacked on theluminescent layer. In this organic EL element, the organic luminescentsubstance is caused to emit light by applying a predetermined voltagebetween the first electrode and the second electrode.

Since the organic EL element is an element of a thin film type asdescribed above, when an organic EL panel having a single or a pluralityof organic EL elements formed on the substrate is used as a panel lightsource of black light or the like, an apparatus having the panel lightsource can be easily thinned. Moreover, when a display device isconstituted by using, as a display panel, an organic EL panel having apredetermined number of organic EL elements as pixels formed on asubstrate, advantages that cannot be provided by a liquid crystaldisplay device are realized such as high visibility and absence of fieldangle dependency.

However, in the case of fabricating an organic EL element, there remainmany technical problems and it is generally difficult to finely patternthe cathode or the luminescent layer (organic EL medium layer) of theorganic EL element because of the poor heat resistance (in general, 100°C. or lower), low solvent resistance and poor moisture resistance of theorganic substance (organic EL medium) used for a charge injection layerand a luminescent layer. For example, it is very difficult to use aphotolithography method, which is normally used for patterning of a thinfilm, for the organic EL element because there is a problem ofdeteriorating characteristics of the organic EL element due to the entryof a solvent in a photoresist into the element, the high-temperatureatmosphere in a resist baking step, the entry of a resist developersolution or an etching solution into the element, the damage by plasmain dry etching and the like.

As a technique for solving the foregoing problems, an organic EL panelhaving little deterioration in an organic EL element and having highreliability and a fabrication method therefor are disclosed in theJapanese Publication of Unexamined Patent Application No. H9-102393.

As a technique for inexpensive and efficient mass production of organicEL displays as described in the above-mentioned publication, a methodand apparatus of a so-called roll-to-roll system may be considered.However, this technique has not been sufficiently studied yet, andconsiderably complicated steps and device structure are required forfabricating a flexible organic EL display by the roll-to-roll system.For example, in the current state, it is quite difficult to pattern acathode or a luminescent layer for the organic EL element at a low coston a substrate of a large area made of a plastic film or the like.

DISCLOSURE OF THE INVENTION

Thus, it is an object of the present invention to provide a method andapparatus for fabricating an organic EL display by the roll-to-rollsystem, which enables continuous and efficient mass production offlexible organic EL displays.

In order to achieve the above-described object, a method for fabricatinga flexible organic EL display according to a first aspect of the presentinvention is adapted for fabricating an organic EL display having acathode, a single or a plurality of luminescent layers made of anorganic substance, and an anode provided on an optically transparentsubstrate, wherein a strip-like flexible substrate made of a plasticfilm or the like is used as the optically transparent substrate, and astep of patterning the luminescent layer and a step of patterning thecathode are carried out in a vacuum by a roll-to-roll system whilemaking the flexible substrate travel continuously.

As the luminescent layer patterning step according to the first aspectof the present invention, it is preferred to pattern the luminescentlayer on the surface of the flexible substrate on which the anode ispatterned in advance and to clean the surface of the flexible substrateby ion bombardment immediately before the luminescent layer patterningstep.

Also, according to the first aspect of the present invention, it ispreferred that at least one of the luminescent layer patterning step andthe cathode patterning step is carried out by vacuum vapor deposition orsputtering using a mask having an opening portion of a predeterminedshape formed therein, and is adapted for forming a stripe pattern havinga width equal to the width of the opening portion on the flexiblesubstrate.

Moreover, according to the first aspect of the present invention, it ispreferred that as the mask, a strip-like mask having opening portionsintermittently formed therein is caused to intermittently travel by theroll-to-roll system at every predetermined travelling length of theflexible substrate in accordance with the roll-to-roll system, and thatthe opening portions which are reeled out are caused to face ageneration source of a patterning substance in the luminescent layerpatterning step and the cathode patterning step.

Furthermore, according to the first aspect of the present invention, itis preferred that a tracking signal is provided on one lateral endportion of the flexible substrate, the position in the longitudinaldirection and the direction of the width of the flexible substrate isdetected by detecting the tracking signal, and the position of theopening portion formed in the mask and the opening and closing timing ofa shutter for starting and stopping the supply of the patterningsubstance to the flexible substrate are controlled on the basis of theresult of detection.

In addition, according to the first aspect of the present invention, itis preferred that the flexible substrate processed in the luminescentlayer patterning step and the cathode patterning step is wound in a rollshape and that the roll is housed in a container filled with an inertgas and is carried to the next step.

In order to achieve the above-described object, a method for fabricatinga flexible organic EL display according to a second aspect of thepresent invention is adapted for fabricating an organic EL displayhaving a cathode, a single or a plurality of luminescent layers made ofan organic substance, and an anode provided on an optically transparentsubstrate, wherein a strip-like flexible substrate made of a plasticfilm or the like is used as the optically transparent substrate, and astep of patterning the luminescent layer and a step of patterning thecathode are carried out in a vacuum by a roll-to-roll system whilemaking the flexible substrate travel intermittently.

In order to achieve the above-described object, an apparatus forfabricating a flexible organic EL display according to a third aspect ofthe present invention is adapted for fabricating an organic EL displayhaving a cathode, a single or a plurality of luminescent layers made ofan organic substance, and an anode provided on an optically transparentflexible substrate made of a plastic film or the like, wherein a step ofpatterning the luminescent layer and a step of patterning the cathodeonto the surface of a strip-like optically transparent flexiblesubstrate are carried out in a vacuum by a roll-to-roll system whilemaking the flexible substrate travel continuously.

According to the third aspect of the present invention, it is preferredto provide an ion cleaning electrode for cleaning the surface of theflexible substrate by ion bombardment immediately before the luminescentlayer patterning step.

Also, according to the third aspect of the present invention, it ispreferred that at least one of the luminescent layer patterning step andthe cathode patterning step is carried out by vacuum vapor deposition orsputtering using a mask, and that the apparatus includes a continuouslyrotating drum for winding the flexible substrate thereon and causing theflexible substrate to travel, a generation source of a patterningsubstance, and a mask arranged between the continuously rotating drumand the patterning substance generation source and having an openingportion of a predetermined shape formed therein.

Moreover, according to the third aspect of the present invention, it ispreferred that the apparatus includes travelling means for causing astrip-like mask, having opening portions intermittently formed thereinto intermittently travel by the roll-to-roll system at everypredetermined travelling length of the flexible substrate in accordancewith the roll-to-roll system, and that the opening portions reeled outby the travelling means are caused to face the generation source of thepatterning substance.

Furthermore, according to the third aspect of the present invention, itis preferred that the apparatus includes a tracking signal provided onone lateral end portion of the flexible substrate and a tracking signaldetection sensor for detecting the tracking signal, and that theposition in the longitudinal direction and the direction of the width ofthe flexible substrate is detected by detecting the tracking signalusing the tracking signal detection sensor, and the position of theopening portion formed in the mask and the opening and closing timing ofa shutter for starting and stopping the supply of the patterningsubstance to the flexible substrate are controlled on the basis of theresult of detection.

In addition, according to the third aspect of the present invention, itis preferred that the apparatus includes winding means for winding in aroll the flexible substrate, processed in the luminescent layerpatterning step and the cathode patterning step, and a container filledwith an inert gas for housing the roll.

Further, according to the third aspect of the present invention (FIGS. 1and 2), it is preferred that a travelling counter 12 for counting thetravelling distance of a flexible substrate 1 and an anode pattern edgedetection sensor 27 for detecting an edge 4 a of an anode stripe pattern4 (having streak-shaped anode patterns formed in a plurality of rowsalong the direction of width of the flexible substrate 1) are providedin the luminescent layer patterning step constituting the apparatus forfabricating a flexible organic EL display, and that a shutter 24 forstarting and stopping the supply of the patterning substance to theflexible substrate 1 and a shutter controller 25 for controlling theopening and closing of the shutter 24 are provided in a patterningsubstance generation source (evaporation source) 23, wherein thetravelling counter 12 and the anode pattern edge detection sensor 27 arecaused to communicate with the shutter controller 25 and whereinpatterning from a front end portion to a rear end portion of the anodestripe pattern 4 along the substrate travelling direction is carried outby controlling the opening and closing of the shutter 24 in theluminescent layer patterning step.

Moreover, according to the third aspect of the present invention (FIGS.1 and 2), it is preferred that the luminescent layer patterning step forforming a luminescent layer pattern 6 (and 7) of another color inparallel with and distanced away at an appropriate space from aluminescent layer pattern 5 in the flexible substrate 1 having the anodestripe pattern 4 formed in the direction of width of the flexiblesubstrate 1 and having the luminescent layer stripe pattern 5 of apredetermined color orthogonal to the anode pattern 4, or the cathodepatterning step for stacking a stripe pattern 8 of a cathode 8 a onluminescent layer stripe patterns 5, 6, 7 in the flexible substrate 1having the anode stripe pattern 4 formed in the direction of width ofthe flexible substrate 1 and having the luminescent layer stripepatterns 5, 6, 7 of predetermined colors formed on the anode pattern 4,is constituted as follows.

That is, it is preferred that a travelling counter 12 for counting thetravelling distance of the flexible substrate 1, an anode pattern edgedetection sensor 27 for detecting an edge 4 a of the anode stripepattern 4, luminescent layer pattern edge detection sensors 42, 52, 62for detecting edges 5 a, 6 a, 7 a of the luminescent layer patterns 5,6, 7, a mask width position controller 45 for adjusting the position ofa mask 28 in the direction of width of the flexible substrate, and anedge position controller 41 for correcting meandering of the flexiblesubstrate 1 on the continuously rotating drum (for example, firstcooling can 21) are provided. It is also preferred that the anodepattern edge detection sensor 27 is caused to communicate with a shuttercontroller 25, the travelling counter 12 is caused to communicate withthe shutter controller 25 and the mask width position controller 45, andthe luminescent layer pattern edge detection sensor 42 is caused tocommunicate with the mask width position controller 45. It is alsopreferred that a shutter 24 for starting and stopping the supply of thepatterning substance to the flexible substrate, and the shuttercontroller 25 for controlling the opening and closing of the shutter 24are provided in the patterning substance generation source.

In order to achieve the above-described object, an apparatus forfabricating a flexible organic EL display according to a fourth aspectof the present invention is adapted for fabricating an organic ELdisplay having a cathode, a single or a plurality of luminescent layersmade of an organic substance, and an anode provided on an opticallytransparent flexible substrate made of a plastic film or the like,wherein a step of patterning the luminescent layer and a step ofpatterning the cathode onto the surface of a strip-like opticallytransparent flexible substrate are carried out in a vacuum by aroll-to-roll system while making the flexible substrate travelintermittently.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view showing the structure of a flexibleorganic EL display fabricating apparatus according to an embodiment ofthe present invention.

FIG. 2(a) is a plan view showing the state where respective patterns aresequentially formed on a film substrate in the fabricating apparatus ofFIG. 1, and showing a substrate which has ITO anodes and extendedelectrodes patterned in a stripe form on the surface thereof in advance.

FIG. 2(b) is a plan view showing the state where respective patterns aresequentially formed on a film substrate in the fabricating apparatus ofFIG. 1, and showing the substrate immediately after a luminescent layerof GREEN is patterned in a stripe form.

FIG. 2(c) is a plan view showing the state where respective patterns aresequentially formed on a film substrate in the fabricating apparatus ofFIG. 1, and showing the substrate immediately after a luminescent layerof BLUE is patterned in a stripe form.

FIG. 2(d) is a plan view showing the state where respective patterns aresequentially formed on a film substrate in the fabricating apparatus ofFIG. 1, and showing the substrate immediately after a luminescent layerof RED is patterned in a stripe form.

FIG. 2(e) is a plan view showing the state where respective patterns aresequentially formed on a film substrate in the fabricating apparatus ofFIG. 1, and showing the substrate immediately after a cathode ispatterned.

FIG. 3 shows a film substrate having a tracking signal formed at its onelateral end portion in the fabricating apparatus of FIG. 1.

FIG. 4 shows an exemplary structure of a mask used for forming adot-like pattern in the fabricating apparatus of FIG. 1.

FIG. 5 shows the state where a dot-like pattern is formed byintermittently feeding a film substrate in the fabricating apparatus ofFIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will now be describedwith reference to the drawings.

FIG. 1 is an explanatory view showing the structure of a flexibleorganic EL display fabricating apparatus. FIGS. 2(a) to 2(e) are planviews showing the state where respective patterns are sequentiallyformed on an optically transparent and flexible plastic film substrateby the fabricating apparatus, and are plan views showing the substrateportion immediately after respective steps. The display fabricatingapparatus is housed in a vacuum chamber (not shown) and is adapted forcontinuously carrying out formation (patterning) of the patterns in avacuum by the roll-to-roll system.

Specifically, the display fabricating apparatus includes a reeling unitA for a plastic film substrate 1 having ITO anodes 2 and extendedelectrodes 3 patterned in advance in a stripe shape on its surface, afirst patterning unit B (first vapor deposition unit) for patterning aluminescent layer of GREEN on the ITO anodes 2 by vapor deposition, asecond patterning unit C (second vapor deposition unit) for patterning aluminescent layer of BLUE in parallel with the luminescent layer ofGREEN by vapor deposition, a third patterning unit D (third vapordeposition unit) for similarly patterning a luminescent layer of RED inparallel with the luminescent layer of GREEN by vapor deposition, afourth patterning unit E (electrode patterning film forming unit) forpatterning cathodes 8a in a stacked state by vapor deposition (orsputtering) on both end portions of the luminescent layers of threecolors, and a winding unit F for winding the substrate 1 from the fourthpatterning unit.

FIG. 2(a) shows the substrate 1 having the ITO anodes 2 and the extendedelectrodes 3 patterned in advance in a stripe shape on its surface. FIG.2(b) shows the substrate immediately after the luminescent layer ofGREEN is patterned in a stripe shape. FIG. 2(c) shows the substrateimmediately after the luminescent layer of BLUE is patterned in a stripeshape. FIG. 2(d) shows the substrate immediately after the luminescentlayer of RED is patterned in a stripe shape. FIG. 2(e) shows thesubstrate immediately after the cathodes are patterned.

On the surface of the strip-shaped film substrate 1 shown in FIG. 2(a),a plurality of electrode patterns 4, each comprising the ITO electrode 2constituting a transparent conductive film as the anode and the extendedelectrodes 3 continuous to both end portions thereof, are formed at anequal pitch in the longitudinal direction of the substrate andorthogonal to the longitudinal direction. The fabricating apparatus isadapted for ultimately stacking stripe patterns 5, 6, and 7 of GREEN,BLUE, and RED on and orthogonal to the electrode patterns 4 and thenstacking the cathode stripe pattern 8 on the stripe patterns of threecolors in a combined manner, as shown in FIG. 2(e).

As is apparent from FIG. 2(e), in the flexible organic EL display to beformed, the stripe patterns 5 to 7 of three colors and the cathodestripe pattern 8 are stacked with high accuracy on the electrodepatterns 4 which are intermittently formed on the substrate 1.Therefore, the flexible organic EL display fabricating apparatusaccording to the present invention needs to have pattern forming meanstherefor and control means for controlling the operation. The structureof the fabricating apparatus will now be described.

The reeling unit A is provided with a reeling shaft 11 for setting thefilm substrate 1 on which the ITO anodes 2 and the extended electrodes 3stacked on both end portions of the ITO anodes 2 in a combined mannerare patterned in a stripe shape, and a travelling counter 12 forcounting the travelling distance of the film substrate 1 reeled out fromthe reeling shaft 11.

As shown in FIG. 2(b), the first patterning unit B is adapted forcarrying out patterning of GREEN from the front end portion to the rearend portion of the electrode patterns 4 in the substrate travellingdirection. The first patterning unit B is provided with a first coolingcan 21, which is a continuously rotating cylindrical drum. Near theouter peripheral surface of the first cooling can 21, there are providedan ion cleaning electrode 22, an evaporation source 23 for forming theluminescent layer of GREEN on the film substrate 1, a shutter 24 foropening and closing a vapor supply port of the evaporation source 23, ashutter controller 25 for controlling the opening and closing of theshutter 24, and a shield plate 26 in the shape of an inverted cone (withits supper portion opened) for surrounding the outer periphery of theevaporation source 23. The opening portion of the shield plate 26 islocated closely to the first cooling can 21 so that a strip-shaped mask28 can intermittently travel in the gap between the opening portion andthe first cooling can 21. In the mask 28, opening portions 28 a areintermittently formed in the longitudinal direction of the mask. The ioncleaning electrode 22 is adapted for cleaning, by ion bombardment, thesurface of the film substrate 1 travelling in close contact with theouter peripheral surface of the cooling can 21 immediately before theluminescent layer patterning step by the first patterning unit B.

An intermittent travelling device for the mask 28 is adapted for feedingto index the mask 28 and locating the next opening portion 28 a rightabove the evaporation source 23 as shown in FIG. 1, when an adheredobject is adhered to the mask 28 to a certain extent by vapor depositionfor a long period of time. This intermittent mask travelling device isprovided with a reeling shaft 31 for setting the mask 28 and a windingshaft 32 for winding the mask 28 reeled out from the reeling shaft 31.The mask 28 is caused to intermittently travel at every predeterminedtravelling length of the film substrate 1 by rotating the winding shaft32, and the opening portion 28 a thus reeled out is caused to face theevaporation source 23. An anode pattern edge detection sensor 27 fordetecting an edge 4 a of the electrode pattern 4 patterned in theprevious step is provided before the first cooling can 21, so that anoutput signal thereof can be transmitted to the shutter controller 25.The travelling counter 12 and the anode pattern edge detection sensor 27are caused to communicate with the shutter controller 25.

The second patterning unit C is adapted for carrying out patterning ofBLUE from the front end portion to the rear end portion of the electrodepatterns 4 in the substrate travelling direction, in parallel with andin proximity with the pattern of GREEN. The second patterning unit C isprovided with an edge position controller 41 (EPC(edge positioningcontrol)mechanism) for correcting the meandering of the film substrate 1on a second cooling can 44, a luminescent layer pattern edge detectionsensor 42 for detecting an edge of the luminescent layer pattern 5, anda mask width position controller 45 for adjusting the position of themask 28 in the direction of width of the film substrate. In place of theevaporation source 23, an evaporation source 43 for forming theluminescent layer of BLUE is provided. The other parts of the structureare similar to those of the first patterning unit B. The anode patternedge detection sensor 27 is caused to communicate with the shuttercontroller 25, and the travelling counter 12 is caused to communicatewith the shutter controller 25 and the mask width position controller45.

The third patterning unit D is provided with an evaporation source 53for forming the luminescent layer of RED, in place of the evaporationsource 43. The other parts of the structure are similar to those of thesecond patterning unit C. The fourth patterning unit E is provided withan evaporation source 63 (or sputtering source) for forming the cathodepattern, in place of the evaporation source 53, and the other parts ofthe structure are similar to those of the third patterning unit D. Thewinding unit F is provided with a winding shaft 71 for winding thesubstrate 1 from the fourth patterning unit E. In the winding unit F, anN₂ purge box 72 for carrying the wound substrate 1 in a roll shape tothe next step is prepared. Inside the N₂ purge box 72, nitrogenreplacement is carried out in advance and nitrogen replacement of theinside can be carried out again after the rolled substrate 1 is housedtherein.

Numerals 52 and 62 in FIG. 1 denote the luminescent layer pattern edgedetection sensors. A numeral 54 denotes a third cooling can, and anumeral 64 denotes a fourth cooling can. These cooling cans are providedwith a mechanism similar to that of the ion cleaning electrode 22 in asimilar manner. The first cooling can 21 through the fourth cooling can64 are rotary cooling drums for preventing thermal deformation of theflexible substrate 1.

The operation of the display fabricating apparatus will now be describedfurther in detail. As shown in FIG. 2(a), the electrode patterns 4comprising the ITO anodes 2 as transparent conductive films and theextended electrodes 3 are patterned on the plastic film substrate 1 inthe preceding step. For this patterning, for example an ordinaryphotolithography method or other method can be employed. The filmsubstrate 1 on which the ITO anodes 2 are already patterned is set onthe reeling shaft 11 of the apparatus of FIG. 1. The substrate 1 reeledout from the reeling shaft 11 passes through several guide rolls 13,then is wound onto the first cooling can 21, and is caused tocontinuously travel from the right side to the left side of FIG. 1 bythe rotation of the cooling can.

The first cooling can 21 is provided with the ion cleaning electrode 22and the first patterning unit, that is, the first EL pattern vapordeposition unit B. The ITO-patterned substrate 1 has its surface cleanedat the ion cleaning electrode 22 as the preprocessing before vapordeposition of the organic luminescent layer. After cleaning, the stripepattern 5 of GREEN, which is the first luminescent layer pattern, isformed at the first EL pattern vapor deposition unit B.

The operation of the first EL pattern vapor deposition unit B will nowbe described. The substrate 1 having the electrode patterns 4 formedthereon is continuously reeled out from the reeling shaft 11, and theedges 4 a of the electrode patterns 4 are detected by the anode patternedge detection sensor 27. The travelling distance of the substrate 1 iscounted by the counter 12 and the travelling position of the edges 4 ais detected. At a time point when the edges 4 a are shifted to slightlybefore the opening portion 28 a of the mask 28, the shutter 24 is openedby the operation of the shutter controller 25, and the deposition fromthe evaporation source 23 is vapor-deposited on the electrode patterns 4of the substrate 1, thus forming the stripe pattern 5 of GREEN as shownin FIG. 2(b). The substrate 1 travels toward the second cooling can 44.

The operation of the luminescent layer pattern edge detection sensor 42and the mask width position controller 45 will now be described. Whenthe substrate 1 having its meandering in the direction of widthcorrected to a certain extent by the edge position controller 41 passesthrough the anode pattern edge detection sensor 27, the edge 4 a isdetected. Then, when the substrate 1 passes through the luminescentlayer pattern edge detection sensor 42, the position of the previouslyformed stripe pattern 5 of GREEN in the direction of width is detected.The output signal of the detection sensor 42 is received by the maskwidth position controller 45.

The mask 28 is shifted and positioned in the direction of width of thesubstrate 1 by an actuator, not shown, and the position of the openingportion 28 a in the direction of width is appropriately corrected inaccordance with the position of the stripe pattern 5 of GREEN in thedirection of width by an instruction from the mask width positioncontroller 45. The edge 4 a on the substrate 1 are already detected bythe anode pattern edge detection sensor 27. When the edge 4 a is locatedslightly before the opening portion 28 a, the shutter 24 is opened bythe operation of the shutter controller 25, and the deposition from theevaporation source 43 is vapor-deposited on the substrate 1, similarlyto the operation of the vapor deposition unit 23, thus forming thestripe pattern 6 of BLUE as shown in FIG. 2(c). Similarly, in the thirdpatterning unit D, the stripe pattern 7 of RED is formed on thesubstrate 1 as shown in FIG. 2(d).

In the above description, the alignment of the opening portion 28 a inthe direction of width may be carried out on the basis of a trackingsignal provided on the substrate 1 for detection of the direction ofwidth. Specifically, as shown in FIG. 3, a tracking signal 81 isprovided in advance at one lateral end portion in the direction of widthof the substrate 1, and a tracking signal detection sensor is providedin advanced at the position where the anode pattern edge detectionsensor 27 is arranged or at a predetermined position preceding theopening portion 28 a. The tracking signal 81 provided on the substrate 1is detected by the tracking signal detection sensor, and the result ofdetection is sent to the mask width position controller 45. The maskwidth position controller 45 appropriately adjusts the position of theopening portion 28 a in the direction of width in accordance with theposition of the substrate 1 on the basis of the result of detection sentfrom the tracking signal detection sensor.

The above-described result of tracking signal detection can be used notonly for alignment of the opening portion 28 a in the direction of widthbut also for controlling the opening and closing timing of the shutter24. That is, the above-described result of tracking signal detection issent to the mask width position controller 45 and also sent to theshutter controller 25. The shutter controller 25 appropriately adjuststhe opening and closing timing of the shutter 24 in accordance with theposition of the substrate 1 on the basis of the result of detection sentfrom the tracking signal detection sensor.

In this case, for example, a magnetic tracking signal, an opticaltracking signal, an electrostatic capacity tracking signal, or anelectric tracking signal can be used as the tracking signal 81, whichmay be properly selected in consideration of various conditions such asthe material of the substrate 1 and the manufacturing environment.

By thus carrying out the alignment of the opening portion 28 a in thedirection of width and the control of the opening and closing timing ofthe shutter 24, the position for forming the stripe pattern of theluminescent layer can be finely controlled in the direction of width andin the longitudinal direction of the substrate 1. The control of thepattern forming position is not limited to the formation of the stripepattern of the luminescent layer and can be similarly applied toformation of the cathode pattern, which will be described later. Thus,it is possible to form an organic EL element of high quality.

At the fourth cooling can 64, the stipe pattern 8 of the cathode 8 a(metal layer pattern) is formed on the stipe patterns 5, 6, and 7 ofthree colors (GREEN, BLUE, and RED) already formed on the substrate 1,similarly as shown in FIG. 2(e). Although the electrode pattern filmforming unit 63 in FIG. 1 uses vapor deposition, it may also be based onsputtering.

Finally, the pattern-formed substrate 1 is wound by the winding shaft71. In order to make an organic EL display, a step of forming anextended electrode and a sealing step are required. However, since theorganic EL layer thus formed is generally easy to deteriorate, the filmwound in a roll is housed in the N₂ purge box 72 and carried to theextended electrode forming step and the sealing step (not shown), whichare subsequent steps.

Although the apparatus according to the embodiment of FIG. 1 isconstituted to carry out formation of patterns of the organic EL layerof three colors (GREEN, BLUE, and RED) and the cathode layer inaccordance with the continuous in-line roll-to-roll system, patternformation of each layer may also be carried out by an independentapparatus of the roll-to-roll system

Moreover, the present invention is not limited to the fabrication of theorganic EL display shown in FIG. 2. That is, though the display of FIG.2 has the stripe patterns, other pattern shapes may also be used. Forexample, a dot-like pattern may be used. In the case of forming adot-like pattern, it can be formed, for example, in the followingmanner.

Specifically, as shown in FIG. 4, the opening portion 28 a of the maskis formed in a substantially square shape in the longitudinal directionof the substrate 1. Then, the substrate 1 is fed to index as shown inFIG. 5, and the substrate 1 is fixed so that a predetermined position ofthe substrate 1, that is, the position for forming the organic ELelement, is aligned with the position corresponding to the openingportion 28 a. The shutter 24 is opened in this state, then vapordeposition is carried out through the opening portion 28 a to form adot-like pattern 82, and then the shutter 24 is closed. Then, thesubstrate 1 is fed to index and the substrate 1 is fixed so that theposition for forming the next dot-like pattern 82 is aligned with theopening portion 28 a. The shutter 24 is opened, then vapor deposition iscarried out through the opening portion 28 a to form the dot-likepattern 82, and then the shutter 24 is closed. By repeating theabove-described operation, the dot-like pattern 82 can be formed at theposition for forming the organic EL element. Except for theabove-described matter, the formation of the dot-like pattern can becarried out by using the same apparatus and method as those in the caseof forming the stripe pattern.

Furthermore, the present invention is not limited to the full-colororganic EL display and can be applied to a single-color display.

INDUSTRIAL APPLICABILITY

According to the present invention, the formation of an organic ELelement on a flexible substrate such as a plastic film or the like inaccordance with the roll-to-roll system, which is difficult in theconventional technique, is made possible, and it is possible tosignificantly lower the manufacturing cost of the organic EL display.

Also, according to the present invention, since the patterning of thecathode of the organic EL element and the organic EL medium layer ismade possible in a vacuum integrated process of the roll-to-roll system,the problem of deterioration of the characteristics of the organic ELelement due to mixture of impurity into the organic EL medium layer canbe prevented, and continuous mass production of organic EL elements ofhigh quality is made possible.

What is claimed is:
 1. A method for fabricating a flexible organic EL display, having a cathode, at least one luminescent layer made of an organic substance, and an anode provided on an optically transparent substrate, wherein a flexible substrate strip made of a plastic film is used as the optically transparent substrate, and a step of patterning the luminescent layer and a step of patterning the cathode are carried out in a vacuum by a roll-to-roll system while making the flexible substrate travel continuously.
 2. The method for fabricating a flexible organic EL display as claimed in claim 1, wherein the luminescent layer patterning step patterns the luminescent layer on the surface of the flexible substrate on which the anode is patterned in advance and the surface of the flexible substrate is cleaned by ion bombardment immediately before the luminescent layer patterning step.
 3. The method for fabricating a flexible organic EL display as claimed in claim 1, wherein at least one of the luminescent layer patterning step and the cathode patterning step is carried out by vacuum vapor deposition or sputtering using a mask having an opening portion of a predetermined shape formed therein, and forms a stripe pattern having a width equal to the width of the opening portion on the flexible substrate.
 4. The method for fabricating a flexible organic EL display as claimed in claim 3, wherein as the mask, a mask strip having opening portions intermittently formed therein is caused to intermittently travel by the roll-to-roll system at every predetermined travelling length of the flexible substrate in accordance with the roll-to-roll system, and wherein the opening portions which are reeled out are caused to face a generation source of a patterning substance in the luminescent layer patterning step and the cathode patterning step.
 5. The method for fabricating a flexible organic EL display as claimed in claim 4, wherein a tracking signal is provided on one lateral end portion of the flexible substrate, the position in the longitudinal direction and the direction of the width of the flexible substrate is detected by detecting the tracking signal, and the position of the opening portion of the mask and the opening and closing timing of a shutter for starting and stopping the supply of the patterning substance to the flexible substrate are controlled on the basis of the result of detection.
 6. The method for fabricating a flexible organic EL display as claimed in claim 1, wherein the flexible substrate processed in the luminescent layer patterning step and the cathode patterning step is wound in a roll shape and wherein the roll is housed in a container filled with an inert gas and is carried to a further processing step.
 7. A method for fabricating a flexible organic EL display, having a cathode, at least one luminescent layer made of an organic substance, and an anode provided on an optically transparent substrate, wherein a flexible substrate strip made of a plastic film is used as the optically transparent substrate, and a step of patterning the luminescent layer and a step of patterning the cathode are carried out in a vacuum by a roll-to-roll system while making the flexible substrate travel intermittently.
 8. The method for fabricating a flexible organic EL display as claimed in claim 7, wherein the luminescent layer patterning step patterns the luminescent layer on the surface of the flexible substrate on which the anode is patterned in advance and the surface of the flexible substrate is cleaned by ion bombardment immediately before the luminescent layer patterning step.
 9. The method for fabricating a flexible organic EL display as claimed in claim 7, wherein at least one of the luminescent layer patterning step and the cathode patterning step is carried out by vacuum vapor deposition or sputtering using a mask having an opening portion of a predetermined shape formed therein, and forms a dot pattern having a width equal to the width of the opening portion on the flexible substrate.
 10. The method for fabricating a flexible organic EL display as claimed in claim 9, wherein as the mask, a mask strip having opening portions intermittently formed therein is caused to intermittently travel by the roll-to-roll system at every predetermined travelling length of the flexible substrate in accordance with the roll-to-roll system, and wherein the opening portions which are reeled out are caused to face a generation source of a patterning substance in the luminescent layer patterning step and the cathode patterning step.
 11. The method for fabricating a flexible organic EL display as claimed in claim 10, wherein a tracking signal is provided on one lateral end portion of the flexible substrate, the position in the longitudinal direction and the direction of the width of the flexible substrate is detected by detecting the tracking signal, and the position of the opening portion of the mask and the opening and closing timing of a shutter for starting and stopping the supply of the patterning substance to the flexible substrate are controlled on the basis of the result of detection.
 12. The method for fabricating a flexible organic EL display as claimed in claim 7, wherein the flexible substrate processed in the luminescent layer patterning step and the cathode patterning step is wound in a roll shape and wherein the roll is housed in a container filled with an inert gas and is carried to a further processing step.
 13. An apparatus for fabricating a flexible organic EL display, adapted for fabricating an organic EL display having a cathode, at least one luminescent layer made of an organic substance, and an anode provided on an optically transparent flexible substrate made of a plastic film, wherein a step of patterning the luminescent layer and a step of patterning the cathode onto the surface of an optically transparent flexible substrate strip are carried out in a vacuum by a roll-to-roll system while making the flexible substrate travel.
 14. The apparatus for fabricating a flexible organic EL display as claimed in claim 13, wherein an ion cleaning electrode for cleaning the surface of the flexible substrate by ion bombardment immediately before the luminescent layer patterning step is provided.
 15. The apparatus for fabricating a flexible organic EL display as claimed in claim 13, wherein at least one of the luminescent layer patterning step and the cathode patterning step is carried out by vacuum vapor deposition or sputtering using a mask, and wherein the apparatus comprises a continuously rotating drum, for winding the flexible substrate thereon and causing the flexible substrate to travel, a generation source of a patterning substance, and a mask arranged between the continuously rotating drum and the patterning substance generation source and having an opening portion of a predetermined shape formed therein.
 16. The apparatus for fabricating a flexible organic EL display as claimed in claim 15, wherein the apparatus comprises travelling means for causing a mask strip having opening portions intermittently formed therein to intermittently travel by the roll-to-roll system at every predetermined travelling length of the flexible substrate in accordance with the roll-to-roll system, and wherein the opening portions reeled out by the travelling means are caused to face the generation source of the patterning substance.
 17. The apparatus for fabricating a flexible organic EL display as claimed in claim 16, wherein the apparatus comprises a tracking signal provided on one lateral end portion of the flexible substrate and a tracking signal detection sensor for detecting the tracking signal, and wherein the position in the longitudinal direction and the direction of the width of the flexible substrate is detected by detecting the tracking signal using the tracking signal detection sensor, and the position of the opening portion formed in the mask and the opening and closing timing of a shutter for starting and stopping the supply of the patterning substance to the flexible substrate are controlled on the basis of the result of detection.
 18. The apparatus for fabricating a flexible organic EL display as claimed in claim 15, wherein a travelling counter for counting the travelling distance of the flexible substrate and an anode pattern edge detection sensor for detecting an edge of an anode stripe pattern are provided in the luminescent layer patterning step, and a shutter for starting and stopping the supply of the patterning substance to the flexible substrate and a shutter controller for controlling the opening and closing of the shutter are provided in the patterning substance generation source, and wherein the travelling counter and the anode pattern edge detection sensor are caused to communicate with the shutter controller, and patterning from a front end portion to a rear end portion of the anode stripe pattern along the substrate travelling direction is carried out by controlling the opening and closing of the shutter in the luminescent layer patterning step.
 19. The apparatus for fabricating a flexible organic EL display as claimed in claim 15, wherein in the luminescent layer patterning step for forming a luminescent layer pattern of another color in parallel with and distanced away at an appropriate space from a luminescent layer pattern in the flexible substrate having an anode stripe pattern formed in the direction of width of the flexible substrate and having the luminescent layer pattern of a predetermined color orthogonal to the anode pattern, or in the cathode patterning step for stacking a stripe pattern of a cathode on luminescent layer stripe patterns in the flexible substrate having the anode stripe pattern formed in the direction of width of the flexible substrate and having the luminescent layer stripe patterns of predetermined colors formed on the anode pattern, a travelling counter for counting the travelling distance of the flexible substrate, an anode pattern edge detection sensor for detecting an edge of the anode stripe pattern, luminescent layer pattern edge detection sensors for detecting edges of the luminescent layer patterns, a mask width position controller for adjusting the position of a mask in the direction of width of the flexible substrate, and an edge position controller for correcting meandering of the flexible substrate on the continuously rotating drum are provided, and wherein the anode pattern edge detection sensor is caused to communicate with a shutter controller, the travelling counter is caused to communicate with the shutter controller and the mask width position controller, and the luminescent layer pattern edge detection sensors are caused to communicate with the mask width position controller, and wherein a shutter for starting and stopping the supply of the patterning substance to the flexible substrate, and the shutter controller for controlling the opening and closing of the shutter are provided in the patterning substance generation source.
 20. The apparatus for fabricating a flexible organic EL display as claimed in claim 13, wherein the apparatus comprises winding means for winding in a roll the flexible substrate processed in the luminescent layer patterning step and the cathode patterning step, and a container filled with an inert gas for housing the roll. 